The unicorn is an equine animal with a horn on its forehead. This horn gives them a dressage bonus.

To be able to cover a unicorn, both parents must be unicorns of the same breed and you must have a unicorn covering session available.
If you follow all of these rules, you have a one in 5 chance of getting a unicorn.

Once you cover a unicorn mare, both the mare and the potential unicorn filly will need 10 real hours before they can be covered.